Discriminating sound and improving the signal to noise ratio (SNR) of sound emanating from a selected source is a problem not limited to the hard of hearing people who wear hearing aids that amplify the background noise as well as the sound that is attempting to be understood. People with effective hearing also face difficulties in hearing performer or speakers when the amplifying system is not properly operating or is not focused on the desired sound source.
Systems for enhancing sounds from particular sound sources generally employ an array of microphones i.e., usually more than 10 and in many cases, closer to 60 as described for example, U.S. Pat. No. 4,696,043 issued Sep. 22, 1987 to Iwahara et al. which employs a linear array of microphones divided into a plurality of sub arrays and utilizes signal processing to enhance the signals emanating from the selected source, i.e., from a selected direction.
U.S. Pat. No. 4,802,227 issued Jan. 31, 1989 to Elko describes another system of sound processing utilizing an array of microphones and emphasizing only those signals emanating from a selected direction and having a specified frequency range.
It will be apparent that any system that employs a large array of microphones is likely to be relatively expensive.
U.S. Pat. No. 4,037,052 issued Jul. 19, 1977 to Doi describes a sound pickup system that utilizes a parabolic mike with a pair of mikes positioned one at each side of the parabolic mike to obtain a particular sound pickup, there are no steering devices in this system. However, the structure includes a system incorporating a primary directional microphone plus at least one pair of auxiliary microphones shielded relative to the direction in which the primary microphone is directed.
U.S. Pat. No. 3,324,472 describes an antenna system where a main antenna is flagged by four peripheral receiving horns, a correction for the main antenna with alignment is calculated based on the discrepancy in the signals received by the antenna and is used to control an electromechanical steering device to adjust the alignment of the antenna. This device is particularly designed for properly directing a satellite mounted antenna system. This device can only be used effectively in the case where there is a single continuous source and applies only to electromagnetic signals.